diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/sched_ext/scx_qmap.bpf.c | 24 | ||||
| -rw-r--r-- | tools/testing/selftests/sched_ext/Makefile | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/sched_ext/non_scx_kfunc_deny.bpf.c | 44 | ||||
| -rw-r--r-- | tools/testing/selftests/sched_ext/non_scx_kfunc_deny.c | 47 |
4 files changed, 98 insertions, 18 deletions
diff --git a/tools/sched_ext/scx_qmap.bpf.c b/tools/sched_ext/scx_qmap.bpf.c index b68abb9e760b..aad698fe294b 100644 --- a/tools/sched_ext/scx_qmap.bpf.c +++ b/tools/sched_ext/scx_qmap.bpf.c @@ -159,13 +159,7 @@ static s32 pick_direct_dispatch_cpu(struct task_struct *p, s32 prev_cpu) static struct task_ctx *lookup_task_ctx(struct task_struct *p) { - struct task_ctx *tctx; - - if (!(tctx = bpf_task_storage_get(&task_ctx_stor, p, 0, 0))) { - scx_bpf_error("task_ctx lookup failed"); - return NULL; - } - return tctx; + return bpf_task_storage_get(&task_ctx_stor, p, 0, 0); } s32 BPF_STRUCT_OPS(qmap_select_cpu, struct task_struct *p, @@ -175,7 +169,7 @@ s32 BPF_STRUCT_OPS(qmap_select_cpu, struct task_struct *p, s32 cpu; if (!(tctx = lookup_task_ctx(p))) - return -ESRCH; + return prev_cpu; if (p->scx.weight < 2 && !(p->flags & PF_KTHREAD)) return prev_cpu; @@ -540,13 +534,9 @@ void BPF_STRUCT_OPS(qmap_dispatch, s32 cpu, struct task_struct *prev) */ if (prev) { tctx = bpf_task_storage_get(&task_ctx_stor, prev, 0, 0); - if (!tctx) { - scx_bpf_error("task_ctx lookup failed"); - return; - } - - tctx->core_sched_seq = - core_sched_tail_seqs[weight_to_idx(prev->scx.weight)]++; + if (tctx) + tctx->core_sched_seq = + core_sched_tail_seqs[weight_to_idx(prev->scx.weight)]++; } } @@ -584,10 +574,8 @@ static s64 task_qdist(struct task_struct *p) s64 qdist; tctx = bpf_task_storage_get(&task_ctx_stor, p, 0, 0); - if (!tctx) { - scx_bpf_error("task_ctx lookup failed"); + if (!tctx) return 0; - } qdist = tctx->core_sched_seq - core_sched_head_seqs[idx]; diff --git a/tools/testing/selftests/sched_ext/Makefile b/tools/testing/selftests/sched_ext/Makefile index 789037be44c7..5d2dffca0e91 100644 --- a/tools/testing/selftests/sched_ext/Makefile +++ b/tools/testing/selftests/sched_ext/Makefile @@ -175,6 +175,7 @@ auto-test-targets := \ maximal \ maybe_null \ minimal \ + non_scx_kfunc_deny \ numa \ allowed_cpus \ peek_dsq \ diff --git a/tools/testing/selftests/sched_ext/non_scx_kfunc_deny.bpf.c b/tools/testing/selftests/sched_ext/non_scx_kfunc_deny.bpf.c new file mode 100644 index 000000000000..9f16d39255e7 --- /dev/null +++ b/tools/testing/selftests/sched_ext/non_scx_kfunc_deny.bpf.c @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Verify that context-sensitive SCX kfuncs (even "unlocked" ones) are + * restricted to only SCX struct_ops programs. Non-SCX struct_ops programs, + * such as TCP congestion control programs, should be rejected by the BPF + * verifier when attempting to call these kfuncs. + * + * Copyright (C) 2026 Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> + * Copyright (C) 2026 Cheng-Yang Chou <yphbchou0911@gmail.com> + */ + +#include <vmlinux.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +/* SCX kfunc from scx_kfunc_ids_any set */ +void scx_bpf_kick_cpu(s32 cpu, u64 flags) __ksym; + +SEC("struct_ops/ssthresh") +__u32 BPF_PROG(tcp_ca_ssthresh, struct sock *sk) +{ + /* + * This call should be rejected by the verifier because this is a + * TCP congestion control program (non-SCX struct_ops). + */ + scx_bpf_kick_cpu(0, 0); + return 2; +} + +SEC("struct_ops/cong_avoid") +void BPF_PROG(tcp_ca_cong_avoid, struct sock *sk, __u32 ack, __u32 acked) {} + +SEC("struct_ops/undo_cwnd") +__u32 BPF_PROG(tcp_ca_undo_cwnd, struct sock *sk) { return 2; } + +SEC(".struct_ops") +struct tcp_congestion_ops tcp_non_scx_ca = { + .ssthresh = (void *)tcp_ca_ssthresh, + .cong_avoid = (void *)tcp_ca_cong_avoid, + .undo_cwnd = (void *)tcp_ca_undo_cwnd, + .name = "tcp_kfunc_deny", +}; + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/sched_ext/non_scx_kfunc_deny.c b/tools/testing/selftests/sched_ext/non_scx_kfunc_deny.c new file mode 100644 index 000000000000..1c031575fb87 --- /dev/null +++ b/tools/testing/selftests/sched_ext/non_scx_kfunc_deny.c @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Verify that context-sensitive SCX kfuncs (even "unlocked" ones) are + * restricted to only SCX struct_ops programs. Non-SCX struct_ops programs, + * such as TCP congestion control programs, should be rejected by the BPF + * verifier when attempting to call these kfuncs. + * + * Copyright (C) 2026 Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw> + * Copyright (C) 2026 Cheng-Yang Chou <yphbchou0911@gmail.com> + */ + +#include <bpf/bpf.h> +#include <scx/common.h> +#include <unistd.h> +#include <errno.h> +#include <stdio.h> +#include "non_scx_kfunc_deny.bpf.skel.h" +#include "scx_test.h" + +static enum scx_test_status run(void *ctx) +{ + struct non_scx_kfunc_deny *skel; + int err; + + skel = non_scx_kfunc_deny__open(); + if (!skel) { + SCX_ERR("Failed to open skel"); + return SCX_TEST_FAIL; + } + + err = non_scx_kfunc_deny__load(skel); + non_scx_kfunc_deny__destroy(skel); + + if (err == 0) { + SCX_ERR("non-SCX BPF program loaded when it should have been rejected"); + return SCX_TEST_FAIL; + } + + return SCX_TEST_PASS; +} + +struct scx_test non_scx_kfunc_deny = { + .name = "non_scx_kfunc_deny", + .description = "Verify that non-SCX struct_ops programs cannot call SCX kfuncs", + .run = run, +}; +REGISTER_SCX_TEST(&non_scx_kfunc_deny) |